In the packaging industry there is a particular need for a plastic film having low melt properties, sufficient strength and other handling characteristics. In particular, in the rubber industry, rubber dispersions with additives are premixed and weighed for packaging in plastic film bags. These plastic bags are presently made from polybutadiene, ethylene-methyl acrylate copolymer, polyolefin or ethylene vinyl acetate copolymers. In the rubber dispersion application, it is desired that the bag melt at the lowest possible temperature so that it will disperse completely in the rubber compound during mixing. If the bag does not melt completely, it will adversely affect processing and the performance of the resulting end product that is fabricated from the rubber compound. Also, high melting bags require disadvantageously higher heat histories on the rubber compound and higher energy costs.
Ethylene vinyl acetate copolymer bags are currently made from films whose lowest consistent melt temperature is about 185.degree. F. or higher. These bags contain an ethylene vinyl acetate copolymer having about 18% vinyl acetate. Other known polymers or blends consistently produce films having melting points in the range of about 185-200.degree. F., thereby resulting in unsatisfactory products. In attempting to achieve a low melt film, other properties in the film must be balanced in order to produce a satisfactory product. In addition to a low melting point, sufficient film strength or modulus must be achieved for use in packaging or handling. In addition, film chemical compatibility may be an important factor in certain industries such as the rubber compounding industry as above mentioned. Also, heat sealability of the film for wrapping or packaging purposes is important.
There is a continuing need for a low melt thermoplastic film that is suitable for many applications, particularly in the wrapping and packaging areas. Also there is a need for using low melting bags as compounding tub liners, where the resulting mixture and liner is added to a high intensive mixer. This insures that all ingredients go into the mixer, increases productivity because tub clean up between mix cycles is eliminated, and extends the wear life of the mixing tub or container. Other desirable properties needed in such films include heat sealability, chemical compatibility, and FDA acceptability.